Effects of postural manipulations on head movements from birth to 4 months of age.

The authors investigated the effects of postural manipulation on head movement control in infants from birth to 4 months of age. Eighteen full-term infants were presented with a card, which was moved from side to side before their eyes in 3 positions: unsupported supine, supported supine, and supported reclined. The results showed a higher proportion of initial position of head at midline and midline-to-side trajectory, improving the alignment of head and trunk; fewer movement units and movement units after peak velocity; lower mean angular velocity and peak velocity; and a broader rotation of the head in both supported positions. Thus, external support of the head promoted head and trunk alignment, improving stability and enabling the infant to execute better-controlled head movements. These findings may be helpful in early intervention and treatment of at-risk infants.